Re-enabled polarity set on the CHIP PWM, fixed issues that caused me to disable that feature to begin with. This could have been a 1 letter change, but I re-eabled tests in the unit test to validate. This will close #61

CHANGELOG.rst

@@ -1,3 +1,10 @@
+0.5.4
+---
+* Re-enabled the polarity setting for PWM based upon Issue #61
+* Fixed a 1 letter bug was trying to write inverted to polarity when it wants inversed (such facepalm)
+* Cleaned up the polarity setting code to work when PWM is not enabled
+* Fixed the unit test for pwm to verify we can set polarity
+
 0.5.3
 ---
 * Fixes to the PWM pytest

debian/changelog

@@ -1,3 +1,12 @@
+chip-io (0.5.4-1) unstable; urgency=low
+
+  * Re-enabled the polarity setting for PWM based upon Issue #61
+  * Fixed a 1 letter bug was trying to write inverted to polarity when it wants inversed (such facepalm)
+  * Cleaned up the polarity setting code to work when PWM is not enabled
+  * Fixed the unit test for pwm to verify we can set polarity
+
+ -- Robert Wolterman <robert.wolterman@gmail.com>  Sun, 26 Feb 2017 20:46:00 -0600
+
 chip-io (0.5.3-1) unstable; urgency=low
 
   * Fixes to the PWM pytest

setup.py

@@ -13,7 +13,7 @@ classifiers = ['Development Status :: 3 - Alpha',
                'Topic :: System :: Hardware']
 
 setup(name             = 'CHIP_IO',
-      version          = '0.5.3',
+      version          = '0.5.4',
       author           = 'Robert Wolterman',
       author_email     = 'robert.wolterman@gmail.com',
       description      = 'A module to control CHIP IO channels',

source/c_pwm.c

@@ -246,13 +246,14 @@ int pwm_set_polarity(const char *key, int polarity) {
         return rtnval;
     }
 
-    if (pwm->enable) {
+    // THIS ONLY WORKS WHEN PWM IS NOT ENABLED
+    if (pwm->enable == 0) {
         if (polarity == 0) {
             len = snprintf(buffer, sizeof(buffer), "%s", "normal"); BUF2SMALL(buffer);
         }
         else
         {
-            len = snprintf(buffer, sizeof(buffer), "%s", "inverted"); BUF2SMALL(buffer);
+            len = snprintf(buffer, sizeof(buffer), "%s", "inversed"); BUF2SMALL(buffer);
         }
         ssize_t s = write(pwm->polarity_fd, buffer, len);  e_no = errno;
         if (DEBUG) {
@@ -271,6 +272,7 @@ int pwm_set_polarity(const char *key, int polarity) {
     } else {
         rtnval = 0;
     }
+
     return rtnval;
 }
 
@@ -527,18 +529,19 @@ int pwm_start(const char *key, float duty, float freq, int polarity)
     }
 
     int rtnval = 0;
-    // Always set polarity first
-    if (iscpro == 1) {
-        rtnval = pwm_set_polarity(key, polarity);
-    }
-    rtnval = pwm_set_enable(key, ENABLE);
     // Fix for issue #53
+    // Always set polarity first
+    rtnval = pwm_set_polarity(key, polarity);
     if (rtnval != -1) {
         rtnval = 0;
-        rtnval = pwm_set_frequency(key, freq);
+        rtnval = pwm_set_enable(key, ENABLE);
         if (rtnval != -1) {
             rtnval = 0;
-            rtnval = pwm_set_duty_cycle(key, duty);
+            rtnval = pwm_set_frequency(key, freq);
+            if (rtnval != -1) {
+                rtnval = 0;
+                rtnval = pwm_set_duty_cycle(key, duty);
+            }
         }
     }
     return rtnval;
@@ -563,9 +566,7 @@ int pwm_disable(const char *key)
     pwm_set_frequency(key, 0);
     pwm_set_duty_cycle(key, 0);
     pwm_set_enable(key, DISABLE);
-    if (pwm->iscpro == 1) {
-        pwm_set_polarity(key, 0);
-    }
+    pwm_set_polarity(key, 0);
 
     if ((fd = open("/sys/class/pwm/pwmchip0/unexport", O_WRONLY)) < 0)
     {

source/constants.c

@@ -85,6 +85,6 @@ void define_constants(PyObject *module)
    bcm = Py_BuildValue("i", BCM);
    PyModule_AddObject(module, "BCM", bcm);
 
-   version = Py_BuildValue("s", "0.5.3");
+   version = Py_BuildValue("s", "0.5.4");
    PyModule_AddObject(module, "VERSION", version);
 }

test/test_pwm_setup.py

@@ -31,27 +31,25 @@ class TestPwmSetup:
         assert int(duty) == 0
         assert int(period) == 500000
 
-    @pytest.mark.xfail(reason="pwm cleanup is doing weirdness for this test")
     def test_start_pwm_with_polarity_one(self):
+        PWM.cleanup()
         PWM.start("PWM0", 0, 2000, 1)
 
         pwm_test = '/sys/class/pwm/pwmchip0/pwm0/'
 
-        #assert os.path.exists(pwm_test) == True
         duty = open(pwm_test + 'duty_cycle').readline().strip()
         period = open(pwm_test + 'period').readline().strip()
         polarity = open(pwm_test + 'polarity').readline().strip()
         assert int(duty) == 0
         assert int(period) == 500000
-        assert str(polarity) == "inverted"
+        assert str(polarity) == "inversed"
 
-    @pytest.mark.xfail(reason="pwm cleanup is doing weirdness for this test")
     def test_start_pwm_with_polarity_default(self):
+        PWM.cleanup()
         PWM.start("PWM0", 0, 2000, 0)
 
         pwm_test = '/sys/class/pwm/pwmchip0/pwm0/'
 
-        #assert os.path.exists(pwm_test) == True
         duty = open(pwm_test + 'duty_cycle').readline().strip()
         period = open(pwm_test + 'period').readline().strip()
         polarity = open(pwm_test + 'polarity').readline().strip()
@@ -59,13 +57,12 @@ class TestPwmSetup:
         assert int(period) == 500000
         assert str(polarity) == "normal"
 
-    @pytest.mark.xfail(reason="pwm cleanup is doing weirdness for this test")
     def test_start_pwm_with_polarity_zero(self):
+        PWM.cleanup()
         PWM.start("PWM0", 0, 2000, 0)
 
         pwm_test = '/sys/class/pwm/pwmchip0/pwm0/'
 
-        #assert os.path.exists(pwm_test) == True
         duty = open(pwm_test + 'duty_cycle').readline().strip()
         period = open(pwm_test + 'period').readline().strip()
         polarity = open(pwm_test + 'polarity').readline().strip()
@@ -83,6 +80,7 @@ class TestPwmSetup:
 
     def test_pwm_start_valid_duty_cycle_min(self):
         #testing an exception isn't thrown
+        PWM.cleanup()
         PWM.start("PWM0", 0)
         PWM.cleanup()